膨润土和沸石在镉污染土壤治理中的应用

采用通过盆栽试验,研究了膨润土和沸石对镉污染土壤的治理效果。结果表明,施加膨润土后不同污染程度土壤的交换态、碳酸盐结合态镉的质量分数都有所下降,铁锰氧化物结合态、有机结合态和残渣态镉的质量分数则有所上升。沸石和膨润土对轻度、中度镉污染土壤都表现出钝化作用,对重度镉污染土壤,膨润土对镉的钝化效果明显,而沸石却起到了激活镉的作用。在不同程度镉污染土壤上,膨润土可增加乌塌菜的生物量,并可抑制其对镉的吸收,降低乌塌菜植株体内镉的浓度,对乌塌菜的生长具有显著的促进作用。沸石对轻度和中度镉污染土壤均可降低乌塌菜植株体内镉的浓度,促进乌塌菜的生长并增加其生物量;对重度镉污染土壤,沸石对乌塌菜的生长影响较小,乌塌菜植株体内镉的积累显著增加。

Application of Bentonite and Zeolite in Dealing Soil Contaminated by Cd

A pot experiment was conducted to study the effects of bentonite and zeolite on soil polluted by Cd.The results showed that the quality score of Cd which was exchangeable and combined with carbonate salt declined,and that of Cd which was combined with Fe-Mn,organic and residual increases after bentonite was exerted in different soil contaminated by Cd.Bentonite and zeolite can inactivate Cd in the mild and moderate soil contaminated by Cd,especially in the soil contaminated by Cd seriously,but zeolite showed the effect of activating Cd.In different degree soil polluted by Cd,bentonite can increase the biomass of Wuta vegetables,restrain the soil absorption of Cd,and decrease the concentration of Cd in Wuta vegetables,all of which play a obvious role of improvement on the growth of Wuta vegetables.To the mile and moderate soil polluted by Cd,zeolite can decrease the density of Cd in Wuta vegetables,promote the growth of Wuta vegetables to increase its biomass.To the soil contaminated by Cd seriously,effect of zeolite is smaller on the growth of Wuta vegetables,and the accumulation of Cd in Wuta vegetables increases remarkably.